Vessel launched to accurately record fish stocks

Monday

Jul 30, 2007 at 12:01 AM

NEWPORT, R.I. — Russell Brown folded his arms across his chest. He glanced over his shoulder at the Henry B. Bigelow, the National Oceanic and Atmospheric Administration's newest fish surveying vessel, its hull and superstructure a blazing chalk white in the morning sun at the U.S. Naval Station.

DOUG FRASER

NEWPORT, R.I. — Russell Brown folded his arms across his chest. He glanced over his shoulder at the Henry B. Bigelow, the National Oceanic and Atmospheric Administration's newest fish surveying vessel, its hull and superstructure a blazing chalk white in the morning sun at the U.S. Naval Station.

"This is a big jump over everything that is out there, except for one Norwegian boat," he said proudly.

Mr. Brown's job at NOAA's Northeast Fisheries Science Center in Woods Hole is to oversee the vessels and scientists who go out and find everything from plankton to whales, from Cape Hatteras to Nova Scotia, and attempt to gauge their abundance, distribution and other ecosystem data.

This science, known as ecosystem surveying, gives vital information to other scientists. Their job is to estimate marine populations so that fishery managers know whether their regulations are working. In the case of New England's $1 billion fishing industry, thousands of fishermen have been cut back to less than 50 days of fishing a year in order to bring back depleted stocks of cod, haddock, flounders and other important commercial species.

Fishermen won't see regulations relaxed until surveys show there are more fish and the population estimates indicate that they are robust enough to take more fishing pressure without becoming overfished again.

NOAA spent $60 million on the Bigelow, and will build two similar ships for the southern and western regions of the country. All this is to replace an aging survey fleet and get better fisheries data. One other ship is already working in the Alaska region.

Nearly 209 feet in length, and over 2,200 metric tons, the Bigelow is nearly twice the tonnage of its predecessor, the Albatross IV. The JFK-era ship was state-of-the-art when it was built in 1962, but today is at least a decade beyond its replacement date.

Mr. Brown said the Bigelow has improvements that should significantly lower the chance of human error and variables getting in the way of an accurate picture of fish counts.

For example, in 2003, the Albatross unknowingly towed its survey net with line of unequal length, and veteran fishermen said that mismatched lines could have caused the net to fish poorly. At the time, low population estimates were driving some of the toughest regulations ever to hit the industry.

Although scientists later found that the lengths did not significantly impact the population data, the message was clear that the technology needed updating.

Fishermen on the Bigelow no longer have to rely on visual markings on trawl wires to ensure both lines, that hold open either side of the net, are equal. The Bigelow's enormous winches are computerized. The amount of line to be let out is entered into a computer on the bridge. Computer screens also show the exact shape and dimensions of the net as it is being towed. Cameras on the net show fish as they are being caught.

In heavy seas, as the boat crests a breaker and tries to pull the net up off the bottom, the winches compensate by automatically lengthening the lines.

But the Bigelow is not just about the net.

"There's been a lot of advances in shipbuilding in the last 40 years," said Michael Jech, a National Marine Fisheries Service fish biologist.

Mr. Jech is in charge of hydroacoustic fish surveying, a technique that uses sophisticated sonar for estimating the population of fish like herring and mackerel that travel in enormous schools.

For fish purposes, the Bigelow is a stealth boat built to sneak up on easily spooked schools of fish. The hull is designed to slice through the water while producing low levels of turbulence.

It is a designed based on the U.S. Navy's need for quieter vessels. Noise from the engine other equipment is kept from being transmitted to the hull, which would broadcast the ship's presence to the world below like beating a drum.

A quiet vessel allows scientists to use sensitive instruments like sidescan, multi-beam sonars and echo responders to find fish and map the ocean bottom.

"The advantages are to try and influence fish behavior as little as possible and to hear much better without background noise," said Mr. Jech.

Jason Link, who investigates relationships in the ocean food web at the science center, said the new ship allows them to refine their knowledge of how the ocean works as a whole. Instead of having to backfill environmental conditions with data from other cruises and sources of information, scientists on aboard the Bigelow will get a fairly comprehensive picture of things like the amount and type of prey, water temperature and salinity, while they are collecting information on target species.

The new vessel appears to be a hit with some fishermen as well. New Bedford fisherman Rodney Avila, with 45 years of commercial fishing experience, was one of several commercial fishermen on a committee that helped design new nets for the Bigelow, replacing an outmoded half century-old design that fishermen said didn't work well in capturing some species.

Friday, Mr. Avila returned from four days on the Bigelow watching one of the nets at work.

"We are tickled pink, both the chairman and I. Everything we saw was positive."

Both the net, and the boat passed the test, said Mr. Avila, who also complimented the Bigelow crew and captain, for how they fished and how they listened to what the fishermen onboard had to say.

"It's a new era," he said.

Doug Fraser can be reached at dfraser@capecodonline.com

Never miss a story

Choose the plan that's right for you.
Digital access or digital and print delivery.